BACKGROUND: Recurrence of squamous cell carcinoma (SCC) following Mohs micrographic surgery is uncommon. However, such cases do exist, presumably because of incomplete excision. Identification of single cells or small clumps of SCC tumor may be extremely difficult and can be compromised by inflammatory reaction. OBJECTIVE: The purpose of this study was to evaluate the benefits of incorporating rapid cytokeratin (CK) stains into Mohs technique. METHODS: Simple modification of standard immunoenzyme techniques allows keratin-specific staining to be achieved in less than 90 minutes on Mohs cryostat sections. We used the rapid labeled streptavidin biotin anticytokeratin method at the stage when no tumor was apparent by hematoxylin and eosin staining in 20 patients with large, aggressive, or recurrent invasive SCCs. RESULTS: In eight cases, single cells or small clumps of SCC tumor were identified utilizing AE-1 monoclonal antibody. These patients subsequently underwent further surgery, including wider tumor resection, superficial parotidectomy, or postoperative radiation therapy. CONCLUSION: The rapid CK antibody staining technique enhances the sensitivity of tumor identification in Mohs micrographic surgery, and should reduce tumor recurrence rates.
BACKGROUND: Recurrence of squamous cell carcinoma (SCC) following Mohs micrographic surgery is uncommon. However, such cases do exist, presumably because of incomplete excision. Identification of single cells or small clumps of SCC tumor may be extremely difficult and can be compromised by inflammatory reaction. OBJECTIVE: The purpose of this study was to evaluate the benefits of incorporating rapid cytokeratin (CK) stains into Mohs technique. METHODS: Simple modification of standard immunoenzyme techniques allows keratin-specific staining to be achieved in less than 90 minutes on Mohs cryostat sections. We used the rapid labeled streptavidin biotin anticytokeratin method at the stage when no tumor was apparent by hematoxylin and eosin staining in 20 patients with large, aggressive, or recurrent invasive SCCs. RESULTS: In eight cases, single cells or small clumps of SCC tumor were identified utilizing AE-1 monoclonal antibody. These patients subsequently underwent further surgery, including wider tumor resection, superficial parotidectomy, or postoperative radiation therapy. CONCLUSION: The rapid CK antibody staining technique enhances the sensitivity of tumor identification in Mohs micrographic surgery, and should reduce tumor recurrence rates.